Microstructure, Ductility and Hydrogen Permeability of Nb-Ti-Zr-Ni Alloys

Abstract

A series of Nb₄₀Ti_xZr₁₂Ni_48−x alloys with different Ti/Ni ratios were prepared by arc melting in a purified argon atmosphere. The Ti/Ni ratio affected microstructures, crystal structures, ductility and hydrogen permeability (Φ) of these alloys. The values of hydrogen permeability Φ for the Nb₄₀Ti_xZr₁₂Ni_48−x alloys increased with increasing temperature and were higher than those of pure Pd above 573 K. Hydrogen permeability at 673 K, i.e., Φ_673K and the volume fraction of the primary phase in the Nb₄₀Ti_xZr₁₂Ni_48−x alloys increased with increasing Ti/Ni ratio. The present work demonstrated that hydrogen permeation properties of the Nb₄₀Ti₂₀Zr₁₂Ni₂₈ alloy are superior to those of the Nb₄₀Ti₁₈Zr₁₂Ni₃₀ one which was reported to be the best one in the Nb₄₀Ti_30−xZr_xNi₃₀ alloys.